I need expert advice here !! Is doing Intervals and Sprints on my mountain bike have the same benefit as doing that on a racer ? I'm asking, cuz where I live there's the perfect place to do my uphill intervals & sprints..but the road to lead me there is accessible by mountain bike.
There should be no real difference between the effects of the intervals as long as you are able to go as hard (i.e. off road terrain/bike does not mean you ride at a lower intensity). Obviously the technique you use will be different when working on the two different bikes; so change bikes every now and again.